全文获取类型
收费全文 | 5473篇 |
免费 | 225篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 67篇 |
儿科学 | 79篇 |
妇产科学 | 49篇 |
基础医学 | 640篇 |
口腔科学 | 110篇 |
临床医学 | 264篇 |
内科学 | 1310篇 |
皮肤病学 | 76篇 |
神经病学 | 265篇 |
特种医学 | 184篇 |
外科学 | 1127篇 |
综合类 | 14篇 |
一般理论 | 1篇 |
预防医学 | 116篇 |
眼科学 | 80篇 |
药学 | 285篇 |
中国医学 | 4篇 |
肿瘤学 | 1067篇 |
出版年
2023年 | 20篇 |
2022年 | 43篇 |
2021年 | 100篇 |
2020年 | 46篇 |
2019年 | 66篇 |
2018年 | 96篇 |
2017年 | 81篇 |
2016年 | 114篇 |
2015年 | 123篇 |
2014年 | 173篇 |
2013年 | 189篇 |
2012年 | 290篇 |
2011年 | 366篇 |
2010年 | 216篇 |
2009年 | 189篇 |
2008年 | 336篇 |
2007年 | 343篇 |
2006年 | 350篇 |
2005年 | 347篇 |
2004年 | 364篇 |
2003年 | 350篇 |
2002年 | 341篇 |
2001年 | 95篇 |
2000年 | 87篇 |
1999年 | 126篇 |
1998年 | 99篇 |
1997年 | 97篇 |
1996年 | 65篇 |
1995年 | 66篇 |
1994年 | 62篇 |
1993年 | 58篇 |
1992年 | 66篇 |
1991年 | 55篇 |
1990年 | 39篇 |
1989年 | 32篇 |
1988年 | 32篇 |
1987年 | 33篇 |
1986年 | 35篇 |
1985年 | 19篇 |
1984年 | 23篇 |
1983年 | 9篇 |
1982年 | 13篇 |
1981年 | 10篇 |
1980年 | 5篇 |
1979年 | 9篇 |
1978年 | 5篇 |
1976年 | 8篇 |
1975年 | 6篇 |
1974年 | 6篇 |
1966年 | 4篇 |
排序方式: 共有5738条查询结果,搜索用时 15 毫秒
1.
2.
Kengo Maeda Shinji Kume Yoshihiko Nishio Shiro Maeda Yasuhiro Nishida Mikio Suzuki Takahiro Nakaguchi Toru Kawabata Osamu Hashimoto Takashi Hisanaga Atsunori Kashiwagi Hitoshi Yasuda 《Clinical neurology》2006,46(4):266-269
We report a 53-year-old woman with severe Graves' ophthalmopathy accompanied by uncontrolled myasthenia gravis. She presented remarkable exophthalmos, chemosis, and restriction of eye movement. Despite plasma exchange, steroid pulse therapy, local injection of steroid, and irradiation, ocular symptoms did not ameliorate. Since optic neuropathy was seen, orbital decompression surgery was performed in the left eye. Bilateral chemosis was improved after the surgery. Five years after surgery, there was no ocular palsy in the operated left eye, but in the contralateral eye. For the good prognosis of the eye movement, orbital decompression might be recommended in the severe Graves' ophthalmopathy accompanied by the optic neuropathy and/or ophthalmoplegia with proptosis. 相似文献
3.
Shoji Kubo Hiroaki Kinoshita Kazuhiro Hirohashi Takatsugu Yamamoto 《Journal of Hepato-Biliary-Pancreatic Surgery》1995,2(1):85-89
A case of cystadenocarcinoma of the liver is reported. The patient was a 73-year-old woman in whom a tumor was detected in
the lateral segment of the liver during a health examination. Ultrasonograms and computed tomograms showed a multilocular
cystic mass. Magnetic resonance imaging (MRI) showed a multilocular lowintensity mass, including a high-intensity portion
and a portal branch compressed by the tumor. MRI with gadolinium showed an enhanced cyst wall. The cystic part of the tumor
became smaller and the solid part became larger over a 1-month period, indicating that the tumor was malignant. Subsegmentectomy
(S3) was performed and cystadenocarcinoma with cystadenoma was diagnosed by histopathological examination. Identification of
changes in the appearance of a tumor should be helpful for the differential diagnosis of cystadenoma and cystadenocarcinoma. 相似文献
4.
Dr. Yoshihiko Hayakawa Ph.D. Allan G. Farman B.D.S Ph.D. D.Sc. William C. Scarfe B.D.S M.S. Kinya Kuroyanagi D.D.S Ph.D. 《Oral Radiology》1996,12(1):11-18
The RVG-4 permits automatic exposure compensation (AEC). The purpose of this investigation was to determine the effects of
AEC on image contrast. Images were made either with or without a dental QA jaw phantom using a fixed image projection geometry.
Exposures were 6.3 through 27.3 μC/kg using an X-ray generator operated at 70 kVp. Region of interest pixel value distributions
were measured at tissue thicknesses in this phantom, and the average pixel values and signal-to-noise ratios (SNR) were calculated.
The use of AEC without an object in place resulted in a disproportionate relationship between pixel value and exposure with
a marked reduction in SNR. The use of AEC on under- and over-exposed images of the phantom simultaneously enhanced image contrast
and reduced SNR. Thus, AEC provides a convenient and quick method for achieving high-contrast images with sub-optimal exposures,
however, this could lead to inappropriate patient dosages if the function is used for over-exposed images. AEC reduces the
SNR and produces disproportionate pixel values relative to exposure. 相似文献
5.
K Takayasu Y Muramatsu N Moriyama S Yamazaki T Takayama S Hirohashi Y Shimamura A Takahashi 《Journal of computer assisted tomography》1992,16(2):212-215
To differentiate focal nodular hyperplasia (FNH) from other hepatic tumors, especially hepatocellular carcinoma, we evaluated the hemodynamics of histologically proved FNH in three patients, two by arterial angio-CT and one by microangiography of the resected specimen. These studies demonstrated the centrifugal blood supply of FNH (early filling of central tumor vessels radiating to periphery, and lobulated tumor stains with central low density area in the late phase), which could not be demonstrated by dynamic CT or hepatic angiography. Arterial angio-CT is useful as a further study, when differential diagnosis of FNH is uncertain by other imaging techniques. 相似文献
6.
One of the most problematic aspects of surgery for hepatocellular carcinoma (HCC) is the frequent development of multiple tumors. Determination of the origin of multiple tumors, i.e., multifocal or metastatic, is important for predicting the clinical course of the disease after surgery. In order to clarify the origin of multiple tumors of HCC genetically, we examined patterns of loss of heterozygosity (LOH) on chromosome 16 for DNA isolated from 43 HCCs resected from 19 patients by analysis of restriction fragment length polymorphism. The cases were classified macro- and microscopically into 3 groups: multifocal origin; metastatic origin; and undetermined. Classification based on morphological features was shown to be well correlated with patterns of LOH in multiple tumors of HCC. Different patterns of LOH on chromosome 16 were detected in 8 of 11 patients with tumors of morphologically multifocal origin, whereas they were detected in none of 5 patients with tumors of morphologically metastatic origin. Among five patients with tumors of morphologically undetermined origin, a difference of LOH pattern among the tumors was detected in two, whereas in the other three, the pattern was identical between the tumors. A different pattern of LOH among HCCs arising in situ showed that they were composed of different clones, strongly suggesting their independent clonal origin and multifocal development. These results show that not only appropriate morphological observation but also examination of the LOH pattern on a particular chromosome is useful in diagnosis of multifocal HCC. 相似文献
7.
8.
Cadherin dysfunction in a human cancer cell line: possible involvement of loss of alpha-catenin expression in reduced cell-cell adhesiveness. 总被引:37,自引:0,他引:37
Y Shimoyama A Nagafuchi S Fujita M Gotoh M Takeichi S Tsukita S Hirohashi 《Cancer research》1992,52(20):5770-5774
A human lung cancer cell line, PC 9, was analyzed to elucidate the molecular mechanisms of dysfunction of cadherin-mediated cell-cell adhesion in cancer. Although PC 9 cells strongly expressed E-cadherin at the cell membrane, which was indistinguishable immunochemically from functional E-cadherin, they did not show tight cell-cell adhesion and had reduced E-cadherin-mediated aggregation activity. Immunoprecipitation with E-cadherin and Western blot analysis revealed that PC 9 cells did not express alpha-catenin, a cadherin-associated protein, suggesting that this was the cause of the cadherin dysfunction in the cell line. In addition, Northern and Southern blot analyses disclosed homozygous deletion of part of the alpha-catenin gene, which might have resulted in the loss of alpha-catenin expression in PC 9 cells. 相似文献
9.
Genetic alteration in carcinoid tumors of the lung. 总被引:1,自引:0,他引:1
Kenji Sugio Toshihiro Osaki Tsunehiro Oyama Mitsuhiro Takenoyama Takeshi Hanagiri Masaru Morita Koji Yamazaki Akira Nagashima Hisashi Nakahashi Yoshihiko Maehara Kosei Yasumoto 《Annals of thoracic and cardiovascular surgery》2003,9(3):149-154
Surgically resected specimens of 13 carcinoid tumors of the lung including nine typical carcinoids and four atypical carcinoids, and eight salivary gland type carcinomas (six mucoepidermoid carcinomas and two adenoid cystic carcinomas) were analyzed regarding p53 expression, loss of heterozygosity (LOH) in chromosome 3p, 9p, and K-ras mutation. The overexpression of p53 was identified in four atypical carcinoid tumors, one mucoepidermoid carcinoma, and one adenoid cystic carcinoma, however, none of typical carcinoids showed p53 immunoreactivity. LOH in 3p14 was demonstrated in three of seven informative cases in all tumors. LOH in 9p was demonstrated in two of five informative cases in all tumors. Two of three cases with LOH at 3p14 had a poor prognosis, one of which also had LOH at 9p. No mutation of the K-ras gene was observed in any of these tumors. These data thus indicate that p53 overexpression might distinguish atypical carcinoid tumors from typical tumors and might therefore be useful as an adjunct modality in the differential diagnosis of pulmonary carcinoid tumors. The presence of LOH at 3p14 or 9p may thus help to identify lung cancer patients with a poor prognosis. 相似文献
10.
Mariko Hosono H. Kobayashi Ryota Fujimoto Kazushige Tsutsui Yoshihiko Kotoura Tadao Tsuboyama Hikaru Hayashi Takashi Nakamura Junji Konishi 《Skeletal radiology》1997,26(9):525-528
Objective. To clarify the MRI features of parasymphyseal insufficiency fractures of the os pubis. Design and patients. MRI was performed in four postmenopausal women with parasymphyseal insufficiency fractures. The diagnosis was confirmed with
plain films in every patient. T1-weighted and T2-weighted images were obtained in four patients using a 1.5-T unit. Postcontrast
T1-weighted imaging was also done in three patients. Results and conclusions. MRI of pubic parasymphyseal insufficiency fracture characteristically demonstrates a hyperintense mass lesion with a hypointense
rim on T2-weighted imaging, showing peripheral and septal enhancement after contrast administration. It is important to have
this entity in mind in patients with osteoporosis, especially in patients with a history of pelvic irradiation for malignant
disease, so as not to misinterpret it as a chondroid tumor or bone metastasis. 相似文献